The more fundamental reason tallow works as a base is biology. Tallow is rendered beef fat, and in Latin the word for tallow, sebum, is also the word for the natural oil your skin produces to regulate moisture and protect the skin barrier.

That's not a coincidence. Tallow's fatty acid composition is remarkably close to human sebum. It's primarily oleic acid (roughly 40 to 50%), palmitic acid (roughly 25 to 30%), and stearic acid (roughly 20%). Those are the same fatty acids your skin is already using to maintain its barrier function